Propeller



0. OHLSON PROPELLER June 15 1926..

Filed August 26, 1925 Patented June 15, 1926.

UNITED STATES; ATENT 1,588,88-i8 FICE.

OLOF OI-ILSON, 01? WEST NE'W'ION, MASSACHUSETTE, ASSIGNOR T GILBERT J.MCCARTHY, OF \VASHING-TON, DISTRICT OF COLUMBIA.

PROPELLER.

Application filed August 26, 1925. Serial No. 52,607.

This invention relates to improvements in propellers and particularly inthe structural arrangement thereof.

An object of the invention resides in providing a propeller structureconformed of a plurality of blade sections of members which have hubportions adapted for intertitting connection to mount the blades inassembled. propeller forming relation.

A further object of the invention resides in providing a propellerstructure wherein the blades and the entire structure is adapted to bemanufactured from strip material so that a plurality of radiallyarranged blades may be provided with hub portions adapted forinterfitting connection to form a rigid assembled propeller structure.

The invention comprehends a novel construction of propeller havingnumerous advantages which are particularly pointed out in the followingdescription and in the claims directed to a preferred form of theinvention, it being understood however, that various changes shape andrelation parting from the may be made in the size,

of the parts without despirit or scope of the ininvention as herein setforth.

In the drawing forming cation part of this appli- Figure 1 is an endelevation of the im proved novel propeller construction.

Fig. 2 disassembled prespective view of the blade sections adapted forinterfitting connection to form a completed propeller.

The novel propeller construction forming the subject matter of thisinvention includes a plurality of independent blade sections and in thepresent case, two blade sections are shown indicated by the numerals 1and 2 respectively. These blade sections include the radial blades 3,the base portions of which extend axially of the the propeller asindicated by while the ends of the blades hub portion of the numeral 4,are twisted out of the axial plane so that they will be rotated by ordirect a current of air axially relative to said propeller.

These blades are formed of strip material and having hub portions 5formed as an integral part thereof joining the blades 3 at the baseportions 4. In the form of the invention illustrated in the drawing, thehub I portionsfi are formed of extending blades, of

arcuate portions 6 from the base portion 4 of the substantiallysemi-circular form At the end of the semi-circular portion 8 is formedanother offset portion 9 from which extends a third arcuate portion 10in adjacent spaced relation to the portion 6 and 06 concentric relativethereto.

As shown in 2 of the drawing, all of the blade sections are of identicalconstruction and when placed in the position shown in Fig. 2, theycomplete propeller structure as illustrated in Fig. 1, inwhich theportions 6, 8 and 10 have interfitting relation and closely contact withone another to form a complete solid propeller hook and at the same timepreventing circumferential movement of the blades and hub sectionsrelative to one another so that a rigid structure results. It is to beparticularly noted that the entire propeller structure is formed ofstrip material and that the offset portions '7 and 9 are sufficient tospace the semi-circular portions 6, 8 and 10 inwardly in steppedrelation equal to the thickness of the strip material from which thesections are formed.

It is to be further noted from an inspection of Fig. 1 that the bearingsurface on the interior of the hub portion is provided. partly in eachof the blade sections and that the same is of substantially truecylindrical form from which the blades extend in radial relation.

It is also to be further noted that the in terfitting relation producedprevents circumferential movement between the blade sectionsdue to theinterfitting relation of the offset portions 7 and 9 respectively.

From the foregoing description it will be readily apparent that asubstantially simple and yet highly practical propeller construction hasbeen provided which may be manufactured of strip material which isadapted for use in the manufacture of numerous types of small sizepropellers such as for fans, gas mixers and the like.

Having thus described my invention, what claim as new is 1. A propellercomprising a plurality of blade sections formed of strip material havinghub portions formed on one end thereof will slidably interfit to form a7 0 including a plurality of arcuate concentric interconnected sectionsadapted for slidable interfitting connection in propeller formingrelation.

2. A propellercomprising a plurality of independent blade sectionshaving mating interfitting hub forming sections including meansproviding self locking cooperationin" propeller forming relation.

3. A propeller comprising a plurality of blade sections havingrhubportions formed on one end for concentric slidable interfittingrelation.

i. A propeller comprising a plurality of blade sections having forconcentric slidable interlitting relation,

hub portions formed and means formed on said hub portions to provideself locking between the sections in assembled relation.

5. A propeller comprising a plurality of blade sectionsformed or stripmaterial having hub portions formedon one end thereof including aplurality of concentric interconnected sections adapted for slidableinterlitting connections in propeller "forming relation, and meansformed at the juncture of said inner connected concentric sections forproviding self locking cooperation of the lade sections.

In testimony whereof I 'afiix my signature.

OLOF' OHL'SON.

